CVE-2026-4438

MEDIUM 5.4

gethostbyaddr and gethostbyaddr_r return invalid DNS hostnames

CVSS Score

5.4

EPSS Score

0.0%

EPSS Percentile

11th

Calling gethostbyaddr or gethostbyaddr_r with a configured nsswitch.conf that specifies the library's DNS backend in the GNU C library version 2.34 to version 2.43 could result in an invalid DNS hostname being returned to the caller in violation of the DNS specification.

CWE	CWE-20
Vendor	the gnu c library
Product	glibc
Published	Mar 20, 2026
Last Updated	Mar 23, 2026

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Affected Versions

The GNU C Library / glibc

2.34 ≤ 2.43

References

NVD ↗ CVE.org ↗ EPSS Data ↗

sourceware.org: https://sourceware.org/bugzilla/show_bug.cgi?id=34015

Credits

Antonio Maini (0rbitingZer0) - [email protected]